The present invention relates to a ventilation control system for an elongated ceiling vent in a building, more particularly such a system including a vent door having a construction enabling a plurality of doors to be abutted together to enable the ventilation system to control virtually any length of ceiling vent opening.
Ventilation systems for farm buildings, factories and other work places may have an elongated ceiling vent opening to provide communication between the interior of the building and the ambient atmosphere to provide proper ventilation for the building. The known systems also include some type of door or damper to open or close the vent opening to regulate flow of air through the vent opening and, hence, the ventilation of the building.
In farm buildings, such as layer houses, the ventilation must be accurately controlled to provide the proper atmosphere within the building to maximize the egg production. Layer houses typically may be between 200 and 600 feet in length and have a plurality of vent openings in the ceiling each running the length of the building. The ceiling vent openings along with the associated doors or dampers are usually located in relatively inaccessible locations in the upper ceiling of the building. Thus, it is desirable for such a ventilation control system utilized in these surroundings to demonstrate reliable performance, since maintenance is difficult and time consuming. The location puts a premium on the reliability of such systems, since they are usually inaccessible for routine maintenance.
The known ventilation control systems include metal doors pivotally attached to the building structure adjacent to the ceiling vent opening and connected to an actuating system to move the doors between opened and closed positions. Due to the significant length of the ceiling vent openings, the weight of the metal doors requires a substantial connection to the building structure and requires a powerful actuator to move the door between the opened and closed positions. While such doors are well known, they have not proven to be entirely successful. The metal doors and the pivot attachments will corrode and rust over time, rendering them inoperative.
Another known system slidably attaches the door to inclined supports on each side of the door. To move the door between the opened and closed position, the actuator pulls the door along the inclined supports. Quite obviously, the friction generated between the doors and the inclined supports will increase over time, given the difficulty of providing routine lubrication and maintenance to the ventilation system. Again, this known type of ventilation control has not proven to be entirely reliable.
Thus, it is believed that a ventilation control system including lightweight doors fabricated from non-corroding and non-rusting materials would provide a significant benefit to the users of such ventilation control systems.